Cutter-head with self-clearing bit



(No Model.)

J. KUEHNLE. CUTTER HEAD WITH SELF CLEARING BIT.

No. 592,790. Patented N 2,1897.

I f Illflll! 1 i 11 I 23 2a NITED STATES PATENT FFICE.

JOHN KUEHNLE, OF CINCINNATI, OHIO.

CUTTER-HEAD Wl TH SELF-CLEARING BIT.

SPECIFICATION forming part of Letters Patent No. 592,790, dated November 2, 1897.

Application filed August 19, 1896. Serial'No. 603,196, (No model.)

To all whom it may concern:

Be it known that I, JOHN KUEHNLE, a citizen of the United States, and a resident of Cincinnati, Hamilton county, State of Ohio, have invented certain new and useful Improvements in Cutter-Heads with Self-Clearing Bits; and I do declare the following to be a clean-full, and exact description of the invention, such as will enable others skilled in the art to which it appertainsto make and use the same, attention being called to the accompanying drawings, with the reference numerals and letters marked thereon, which form a part of thisspecification.

This invention relates to improvements in cutter-heads occurring in certain classes of woodworking machinery, particularly in friezers.

It relates more particularly to such friezer cutter-heads which are reversiblethat is, which may be used for cutting while rotating in either direction to suit the convenience of the operator, the character of the work, or the nature of the wood. The bits used on these cutter-heads must be set so that they clear themselvesthat is, no parts of them back of their cutting edge must come in contact with the wood after such cutting edge has once passed through the latter. While they may be set right to clear themselves when the cutter-head is rotating in a certain direction, it does not necessarily follow. thatfthey will also clear themselves when the; direction of rotation of the cutter-head is reversed and the bits must accordingly be reset. To avoid such resetting of the bit every time whenthe direction of rotation of the cutter-head is reversed, cutter-heads have been provided which permit thebits to reset themselves, and my invention relates to certain new features of construction of such a cutter-head, which, together with its operation, is described and pointed out in the following specification and claims and illustrated in the accompanying drawings, in which Figure 1 is a side elevation of the Whole cutter-head in position. Fig. 2 is a vertical centralsection of thesame. Fig. 3 is a top view of it with the bits in operation and the washers whichhold them removed. Fig.4 is a sideview of the bit-centers, and Figs. 5 and movement of the work;

6 are detached detail views of parts whereby the bits are held in position and adjusted.

In the drawings, 8 indicates the upright shaft or spindle, which at its upper'end carries the cutter-head with the bits 9. It projects through and above a table 11, upon which the work 12 is supported while being acted upon by the cutter-head. This latter consists, substantially, of certain means.like two washers 13 and 14:, for instance-between which the bits are held, pivotal supports for .the latter, and other necessary parts whereby the washers are held in position.

The intermediate washer 16 is of no further significance, except as to fill out the space between washer 14 and nut 15 and provide for adjustment in this way: that when higher or lower bits are used washers of different thicknesses (such being at hand) are inserted to compensate for the diiference.

The bits are constructed by turning in reverse the profile required for a certain molding on a circular piece of steel, which is then cut up on radial lines, providing at once a number of bits, usually ,four. The edges arising at the lines of division form the cutting edges 17. The advantage of a bit thus constructed is that it may be readily resharpened on aradial line, whereby the correct profile is always preserved and requires no looking after.

In the drawings those edges indicated by a are supposed to be cutting now, considering direction of rotation of the cutter-head and It is necessary that no parts of the bitthat is, of its outer surface-project or are even in line with the circular path of its cutting edge, so that no part except the latter comes in contact with the work to prevent friction and tearingof the wood. For such purpose the bits are given what is termed clearance, which is done by setting them slightly eccentric to the line of rotation, whereby the necessary clearance is readily obtained. In Fig. 3 this clearance is indicated by I), being the space between the outer surface of the bit and the line of rotation of its cutting edge,; (indicated-by c.) v

In order to enable the bits to provide for themselves the necessaryclearance when the rotation of the cutter-head is reversed, they are pivotally support-ed in a manner to have a limited but sufficient lateral motion either way, so that when the cutting edge comes first in contact with the wood the bits yield to the extent of this movement, whereby the necessary clearance is obtained, and after which they maintain such position.

The details of this construction are as follows: The backs of the bits are cut out, as shown at 18, to form bearings for pivotal supports substantially in form of pins 19, which are rigidly maintained in position on the cutter-head and which form the centers on which the bits swing, as above described. These pins or bit-centers are connected to a sleeve 21, which fits around the upper reduced part of spindle S, and whereby the two centers may be placed at once and are held evenlythat is, with each otherin position.

The bits are simply slipped over pins 19 and rest on washer 13, with sufficient space between their backs and sleeve 21 to permit them to go through the motion which their adjustment requires. This sleeve 21, with the bit-centers, is rigidly held in position on the cutter-head by being clamped between two washers, or, as in this case, between a washer 1i and the upper end of a sleeve 22, aided by openings 23 in washer 13, into which the lower ends of pins 19 reach and thereby prevent slipping of the bits and their support.

It is to be observed that only sleeve 21, with the bit-centers, is rigidly clamped between the parts of the cutter-head, while the bits themselves are notthat is to say, washer 14 does not bearfully on the upper edge of their shouldersthe object being to permit the bits to slip from one side to the other and provide for themselves the necessary clearance whenever the rotation of the cutter-head is reversed. This freedom or looseness of the bits should, however, be limited, for if too much it may cause them to shake or vibrate, and it should, therefore, only be sufficient to permit a bit to turn and adjust itself when its cutting edge strikes the wood. In order, therefore, to obtain the degree just proper for this adjustment of the bits, sleeve 22 is vertically adjustable, whereby sleeve 21, with the bit-centers, becomes also adjustable independently of the bits and may be slightly elevated above them, thus preventing washer let from bearing fully on them. But for this vertical adjustment, which is very desirable for the reasons stated, the bits might be held directly between and by washers 13 and 14. This vertical adjustment of sleeve 22 is obtained by a collar 24:, which rests loosely on a shoulder 25 of spindle 8 and has for part of its height a counterbore 26, which enters from above and receives the lower part of sleeve 22.

By means of a pin 27 occupying a vertical groove 28 in the outside of the sleeve 22 the latter is caused to rotate with collar 24 whenever the latter is rotated. The sleeve is threaded externally and fitted into the thread of washer 13, so that when the latter is held by one hand while collar 24 is rotated with the other sleeve 22 will be screwed either into or out of washer 13, according to the direction of rotation, and accordingly rise or lower. This is because pin 27 constantly occupies groove 28, thereby causing rotation of sleeve 22, while said groove in the latter permits at the same time its independent vertical movement. The same effect may be obtained by reversing the manipulation-that is, by holding collar 2% and rotating washer 13. \Vhen the proper positionthat is, heightof the bit support or centers 19 21 19 is thus found, sleeve 22 may be locked in its adjusted position within washer 13 by means of a setscrew 29, which presses a gib 31, forming part of washer 13 and similarly threaded, against sleeve 22. After this nut 15 at the upper end of the spindle is tightened and the cutter-head is ready for work. A scale is provided around the upper edge of collar 24, which, in conj unction with a mark 32 on washer 13, indicates the relative position of the parts after once adjusted, so that when the number of the graduation on collar 24 opposite the mark on the washer is noted the parts are quickly put in the same position again when the cutterhead is ever taken apart, as for sharpening the bits or for any other reason.

IIaving described my invention, I claim as new 1. In a cutter-head of the kind described, the combination of the bits, center pins 19 on which they are pivotally supported, a sleeve 21 which carries the cen ter pins and washers above and below these parts to clamp them in position and a screw-connected sleeve 22 carried by one of the washers and the end of which forms a part of the clamping-face thereof and particularly that part which supports sleeve 21, while the other part supports the bits, such two parts of the clamping-face of said washer being independently adjustable on each other, so that the bits and their supports may be held with a clamping-pres sure diiferent from each other.

2. In a cutter-head of the kind described, the combination of the bits, a bit-center support on which they are pivotally held, a washer 13 on which the bits rest, a washer 14 above them and a sleeve 22 between which the bitcenter support is held firmly in position, said sleeve 22 being independently adjustable between the washers permitting clamping of the bit-center support independently of the bits.

3. In a cutter-head of the kind described, the combination of an internally-threaded washer 13, an eXternally-tlneaded sleeve 22 inside of it, the two supported on the drivingspindle which passes through the sleeve, a bit-center support resting on the upper end of sleeve 22, bits resting on washer13 and pivotally held on the bit-center support, and a top washer which holds the latter down on sleeve 22.

4. In a cutter-head of the kind described, the combination of an internally-threaded washer 13, an externally-threaded sleeve 22 inside of it, the two supported on the drivingspindle which passes through the sleeve, means to lock this washer to sleeve 22, a bitcenter support resting on the upper end of sleeve 22, bits resting on washer 13 and pivotally held on the bit-center support, and a top washer which holds the latter down on sleeve 22.

5.. In a cutter-head of the kind described, the combination of an internally-threaded washer 13, an externally-threaded sleeve 22 inside of it, the two supported on the drivingspindle which passes through the sleeve, a bit-center support resting on the upper end of sleeve 22, bitsresting on washer 13 and pivotally held on the bit-center support, a collar 24 whereby sleeve 22 may be adjusted and a top washer which holds the parts in position after adjustment.

6. In a cutter-head having automaticallyreversing bits, the combination of a spindle, bits and center supports for them, on which they are pivotally held," washers above and below these bits and their supports between which these parts are clamped in position on the spindle, one washer being independently adjustable thereon so as to permit a variation and adjustment in the clamping action with which the washers engage respectively the bits and their supports for the purpose of holding these latter rigid, but permitting the former to swing thereon.

In testimony whereof I hereunto aflix my signature in presence of two witnesses.

JOHN KUEHNLE.

Witnesses:

C. SPENGEL, ARTHUR KLINE. 

